Steam boiler with a feed water preheater



March 17,1942. B. JOHANSSON.

STEAM BOILER WITH A FEED WATER PREHEAT ER Filed- Nov. 14,- less 4 Sheets-Sheet 1 l l l I I 1 l l I March 17, 1942. B. JOHANSSON 2,276,780

STEAM BOILER WITH A FEED WATER PREHEATER Filed Nov. 14, 1938 -4 Sheets-Sheet 2 4 Sheets-Sheet 3 B. JOHANSSON Filed Nov. 14, 19:3

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STEAM BOILER WITH A FEED WATER PREHEATER March 17, 1942.

W :M%MMMH%MMHHMMHMMMMMMMMHMMLWWMHHHM March 17, 1942. B. JQHANSsON STEAM BOILER WITH A FEED WATER PREHEATER Filed Nov. 14, 1938 4Sheets-Sheet 4 Patented Mar. 17,1942

STEAM BOILER WITH A FEED WATER PREHEATEE Eirger Johansson, Jonkoping, Sweden Application November 14, 1938, Serial No. 24%),415 In Sweden March 12, 1938 3 Claims.

The present invention relates to a vertical steam boiler provided with a feed water preheater and preferably made as a double-walled cap, which distributes the water in the thinnest possible layer round the source of heat.

One purpose of the invention is to give the feed water preheater a lively heat supply inter alia in order to obtain an excess of hot water, which may be used for other purposes than to satisfy the requirements of preheated feed water of the boiler, for example, for warm baths, central heating, dish washing etcetera. For this purpose the invention may be embodied in various ways as will be clear from the following description.

Another purpose is to give the boiler a shape that facilitates and, consequently, simplifies the manufacture.

Still another purpose is to provide the boiler with an electrical heating device in order to enable the utilization of the advantageous properties of electrical energy as a source of heat at places where electrical energy is cheap.

A general purpose is to provide the boiler for rapid boiling and for a high efficiency.

Some embodiments of the boiler are substantially diagrammatically illustrated in the accompanying drawings.

Figures 1 and 2 show the outside of one embodiment from two different sides, Figure 2 showing it when viewed from the left in Figure 1.

Figure 2a is a vertical section taken through the boiler viewed from the same side as Figure 2 Figure 3 shows another embodiment entirel diagrammatically in vertical section.

Figure 4 is a vertical and axial section view of a third embodiment.

Figure 5 is a top view of the same embodiment.

Figures 6 and '7 show a regulator, belonging to the boiler, in sections on the lines VIIVII and VI-VI, respectively.

be said to form a cap around the furnace 4,

whereby the water is divided into a thin layer above, beneath and around the furnace. The steam space of the boiler is located above the furnace and forms the upper portion of the interspace 5. In the embodiment shown in Figures system is connected to the upper header 5. 1.

indicates the smoke outlet, which is provided in the top of the furnace, and which leads to an interspace H between the boiler proper A and the feed water preheater and from this interspace one (possibly several) smoke pipe l2 leads through the preheater B.

In the waterleading connection C1 between the boiler A and the container B there is the valve device C, controlled by the water level in the boiler, for supplying-the hot waterin time with the formation of steam, which is formed rapidly because of the narrow and, as regards volume, very limited header. One embodiment of this regulator is shown in Figs. 6 and '7 and is hereinafter described.

According to the present invention the feed water preheater'B is combined with a heat radiator for hot water, which may be embodied, as is shown in Figures 1 and 2, as a water jacket 2! surrounding the preheater (or as a heating element [not shown in the drawing] provided inthe preheater) which jacket communicates with the header of the boiler by means of pipe line 22 leading up to the upper portion of the radiator, in the drawings the water jacket 21 (or heating element). Hereby the feed water preheater will be subjected to heating on, one hand by the flue gases, flowing through the outlet 7 into the space H beneath the preheater and through the pipe 12 to the chimney, and on the other hand by hot water from the boiler, said water entering the water jacket 2! (or heating element) through the pipe line 22 and flowing back therefrom to the boiler through the pipe line 23.

In the embodiment according to Figures 1 and 2 the water jacket (or heating element) is provided with an expansion outlet with the ap pertaining pipe 25, said pipe extending up to a level higher than the level corresponding to the normal steam pressure of the boiler. By means of the devices described an automatic heating of the feed water is obtained, when an insufficient quantity of steam is taken from the boiler.

The embodiment shown in Figure 3 differs from the embodiment illustrated in Figures 1 and 2 substantially thereby that the preheater is provided within the jacket 2|, so that there will be an interspace 24 between the preheater and the jacket meant for the passage of the flue gases from the furnace 4. To this space a smoke outlet 24a is connected. Consequently, the interspace 24 and the smoke outlet 24a replace the pipe l2. Hereby the fire surface is still more increased.

Both of the described embodiments are characterized by an extremely simple construction and may be used at any place, where a rapidly fired and effective steam boiler for boiling and hot Water heating is required.

The embodiment shown in Figures 4 and 5 relates, in the first place, to the provision of the boiler with an electrical heating device instead of the fuel furnace, and, in the second place, to details in the way in which the boiler may be embodied.

In this embodiment the steam boiler proper A consists of the header and the steam dome 3| located above it. The feed water preheater or the hot water heating apparatus B is located at some distance above the top of the steam dome 3 I, so that there will be an interspace 32 between this roof and the bottom of the preheater B. Said preheater is surrounded by a hot water jacket 2! communicating with this interspace, which hot water jacket is connected to the header 30 of the boiler on one hand through an ascending pipe line 33 and on the other through a descending pipe line 34, the latter via the interspace 32, which is filled with water during the operation.

The pipe line 33 extends from the header of the boiler upwards through the hot water heating apparatus B to the upper portion of the hot water jacket 2|, the descending pipe line 34 from the interspace 32 reaching down into the header of the boiler.

The preheater B, through a pipe line 35 communicates with the header of the boiler via the float-chamber C and this pipe line contains the valve or regulator, which is controlled by the water level in this header, said regulator in turn controlling the supply of water to the boiler in in order to secure the return of the water into pipes 35111, 35:12.

The heating of the boiler is effected by means of an electrical heating element, which, for example, consists of a number of resistance rods 39 provided in tubes 38. Outside the boiler switches 40 for the current supply are provided. This electrical heating element is preferably located in the middle of the header of the boiler. Of course it may be of various constructions and also provided in another way than is shown.

Since the header of the boiler proper is meant to occupy a very little part of the volume of the boiler, (compare the level line and the preheater is able to keep the feed water at a relatively high temperature thanks to the fact that it is surrounded by a hot water jacket, the formation of steam will be very rapid. The fact, that the ascending pipe line 33 to the hot water jacket 2| passes through the preheater, also contributes to this result. A hot water battery may possibly be connected to the ascending pipe line or in some other way be connected to a circulatime with the formation of steam. In the drawup into the hot water jacket, when the steam pressure has reached the height necessary herefore. As shown in Fig. 5 35a indicates a pipe line provided with a water seal and leading to receptacle 35b.

The pipe line 35a and the receptacle 35b have the following function:

The pipe line 35a contains water in both legs 35m and 35m and therefore serves as a safety valve. If the pressure is too high the water is pressed up into the expansion vessel 3%, and at still increasing pressure the steam finally flows through this water out into the open. It will consequently be the difference of height between the two liquid columns that determines the pressure in the boiler. This pressure will reach its maximum when all the water in the leg 35a1 has been expelled. The whole liquid column of the leg 35112 then corresponds to thesteam pressure. 350 is a pipe connecting the expanding receptacle 351) with the lowest part of the pipe 35a tion from the header of the boiler for preheating the water in the container 3. Through the effective preheating large quantities of hot water can be attained, and a considerable part thereof be utilized for other purposes beside the steam.

The regulator shown in Figures 6 and 7 comprises the float chamber C communicating with the boiler A (see Figure 4) a double-armed lever 4| provided in said chamber and made as a balance-beam, onearm of which, the one to the left on Figure '7, carries a weight '42 in'the shape of a ball, which is made of a material of a relatively low specific gravity, the other arm having a weight 43 of a material of a relatively high specific gravity. The'weights 42 and 43 are adjusted relatively to each other with respect to the positions (see nuts 53) as well as in such a way that the weight 42 has a greater absolute Weight than the weight 43, which results therein that the former weight, when there is no water, will press down the left balance arm. The lever 4| has, at 44, jointed connection with a valve 45 in such a manner that the valve is closed, when said weight rises but is opened, when the weight sinks. The valve preferably consists of a ball, which by means of a pivot 4! has jointed connection with the lever 4|, and a conical valve seat 46, against which the ball'45 is pressed and tightens, when the weight 42 rises. Of other parts the reference numeral 58 indicates a small bearing bracket for the lever 4!, and 5| the valve box with connecting piece 52.

It is not necessary to provide the level regulator in a special float chamber, but it may also be placed directly in the boiler.

The described regulator functions in the following manner:

When the balance arm assumes the position. shown in Figure 7, the feed water flows through the valve 45, 46 into the float chamber C. According as the Water level in this chamber rises, the weight 42 will also rise, since it, because of its larger volume, is subjected to a greater lifting force than the weight 43. This has the consequence of the valve ball 35 being pressed against the seat 46, whereby the valve is closed and the supply of feed water ceases. When the level in the float chamber sinks again, the weight 42 sinks also, whereby the valve .45 opens againand new .feed water enters through the valve to the float chamber.

The regulator being embodied as a doublearmed balance-beam with well adjusted weights a reliable mode of operation is provided for.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A steam generating system comprising a furnace, a relatively small boiler associated with said furnace, a feed water preheater, means connecting said preheater and said boiler, a water jacket surrounding said preheater, means connecting said water jacket and said boiler so that hot water from said boiler may heat said preheater and a float-controlled valve controlling said first named connecting means in order to control the water passing from said preheater to said boiler.

2. A steam generating system comprising an electric furnace, a relatively small boiler associated with said furnace, a feed water preheater,

a water jacket surrounding said preheater, a conduit connecting said jacket and said boiler so that hot water from said boiler may heat said preheater and a float-controlled valve controlling the supply of water from said preheater to said boiler.

3. A steam generating system comprising an electric furnace, a relatively small boiler associated with said furnace, a feed water preheater superposed above said boiler, a water jacket surrounding said preheater, an ascending pipe line communicating with said water jacket and said boiler, a descending pipe line communicating with said boiler and said water jacket, a supply pipe line connecting said preheater and said boiler and a valve in said pipe line controlling the supply of water from said preheater to said boiler and therefore the water level in said boiler.

BIRGER JOHANSSON. 

